patten



(No Model.) 2 Sheets-Sheet l.

P. J. PATTEN.

METHOD OF OPERATING ELECTRIC MOTORS. No. 410,988. Patented Sept. 10,1889.

ivd/tmwow Smwmboz 21;; @31 amm N. PEIERS. Pmo-Llmo n' mh Waihin m, 11c

(No Model.) 2 Sheets-Sheet 2.

F J. PATT METHOD OF OPERATING EL 10 MOTORS.

No. 410,988. Patented Sept. 10, 1889 UNITED STATES PATENT OFFICE.

FRANCIS JARVIS PATTEN, OF NINV YORK, N. Y.

METHOD OF OPERATING ELECTRIC MOTORS.

SPECIFICATION forming .part of Letters Patent No. 410,988, datedSeptember 10, 1889.

Application filed July 24:, 1889. Serial No. 318,505- (No model.)

To to zqhom it may concern.-

Be it known that I, FRANCIS JARVIS PAT- TEN, a citizen of the UnitedStates, residing at New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements inDynamo-Electric Machines and Motors, of which the following is adescription.

My invention consists, mainly, in a novel method of operating electricmotors on alternating-current circuits, by which I secure results nototherwise'obtainable, the principal object being to produce an operativeselfstarting alternating-current motor by a simple modification of thearmatin'e-connections of a direct-current machine of any type, andconstitutes, essentially, a new method of operating electric motors onan alternating-current circuit, by which such motors may be driven bythe rapidly-alternatin g impulses of such a circuit in a continuousdirection, said method involving, essentially, a redirecting of theimpulses in the motor-circuits, so that a practically constant currentcirculatesin said circuits, and a constant magnetic relation ispreserved between the field-magnet and armature of the machine.

Figure 1 illustrates the method as applied to a machine of the Grammetype. Fig. 2 illustrates the method as applied to a motor having a drumor cylinder windin Fig. 3 is an enlarged detail sketch of the system ofconnecting the two commntators.

My object is to produce a simple and efficient alternating-currentmotor. It is well known that s'u ch machines have peculiarqualitiesdifficulty of starting, synchronous motion necessitating highspeed at the start and indifierent direction of rotation of the movingpart, rapid reversals of polarity in the cores, inducing heat, withconsequent waste of energy, and other defects.

The machine I have invented, as will be made obvious, is a positivelyself-starting machine. Further, it has but one direction of rotation andcannot start indiiferently in either direction. It is not a synchronousma chine, and the reversals of current direction do not producereversals of polarity of any iron when the machine is in motion. It ispreferably a single field or two-pole machine, instead of beingmultipolar, as usual.

In 1, R R is [an ordinary continuouswound Gramme ring revolving betweenthe two field-poles N N and SS, and it is proposed to so modify theconnections of this ring as to produce an alternating-current motorhaving the qualities above set forth. It is well known that a Grammering is essentially adirect-cu rrent apparatus, and its so-calledcommutator is actuallynothin g more than a collector, there being norectification of the direction of opposed currents, as in other forms ofwinding, and the ring maybe divided into any number of coils, so called,depending only upon the numberof bars in the collector. For conveniencethe winding of the ring R R is divided into twelve coils, numbered 1 to12, around the ring to the right, and the ordinary collector of twelvebars is shown'inside the ring, connected in the ordinary way tocorresponding points of the ring-winding. If, now, current should becaused to flow in the windings of the ring from the upper point 8' downto the right and left to the point a, and so out of the ring, such acurrent would induce in the core of the ring a south pole at s and anorth pole at n, and placed in the field, as shown, rotation would ensuein the direction indicated by the arrows r and T and motion wouldcontinue in this direction as long as the current flowed in the samedirection through the ring-winding-i. 8., from s downward in the rightand left hand halves to n. It is now proposed to bring about this sameresult with an alternating current which is rapidly reversed indirection by so connecting the same ring to another commutatorthat thecurrent will still flow continuously in the same direction in thering-winding, irrespective of its rapid reversal in the externalcircuit. In other words, it is proposed to maintain a constant unchangedsouth polarity in the ring at s and a north polarity at n by means of analternating current, and this without rectifying the alternating currentby means of a commutator. The result rests upon the followingfundamental principle, that if a current of one direction produces agiven polarity in a coil, then a current of opposite direction can bemade to produce the same polarity in the same coil by sending thisreversed current through the same coil in a direction opposite to thatin which the first current was sent. Thus, for illustration, if, say, aplus current flowing downward through the coils of the ring from s to nproduce a south pole at s and a north pole at n, then a reversed orminus current would produce the same polarity at s and 'n if sentthrough the ring in the opposite direction-i. 8., from the point 'n'upward to the right and left to s. Now the machine has, besides theordinary collector f f &c., a commutator of an equal number of bars,(shown outside the ring for convenience at'a a a to 00 and I call this acommutator because it operates to reverse not the currents themselves,-as usual, but the points at which opposed currents shall enter the ring,and it is actually a brush-changer.

In further illustration of the principle used, it may be stated that ifan alternating current were sent into a Gramme ring through the brushesbearing on its collector, and the brushes could be made to changeposition mechanically at each reversal of the current, the machine wouldthen be self-startin g, armature polarity would be constant, motionwould be continuous, and it would act precisely as when supplied with adirect current; The external commutator a a &c., has pre-' cisely thiseffect, for itis so connected to the winding of the Gramme ring R R thatas the brushes m b m 1) bearing on it pass succes sively from onesegment or bar to the next the current sent to the ring is caused toenter the ring from opposite sides,- so that reversed currents sent intothe ring-winding through successive segmentswould maintain apermanentsouth pole at the point 3' and a permanent north pole at n, as, for thereason before explained, opposite currents are caused to flow throughthe ring in opposite directions. Examining, first, the connections ofthe Gramme ring to the collector f f f and to the commutator a a a &c'.,we find the former connected to the ring-winding as an ordinaryGramme-ring collector. The latter, however, is not so connected, for thesegment a and all the odd-numbered segments are connected direct to theturns of the ring immediately beneath themsegment a to coil 1 1 of thering, a to coil 3, a to coil 5, a, to coil 7, a to coil 9, and a to coil11; but the evennumbered segments are not so connected.- Thus segment ais connected to coil 8 on the opposite side of the ring from thissegment, a similarly to coil 10, a to coil 12, a to coil 2, a to coil4:, and a to coil 6 of the ring. Thus all odd-numbered segments areconnected to points of the ring-windingimmedt ately beneath or overthem, and all even-hum bered segments are connected to coilsdiametrically opposite in position to these segments. If, therefore,positive or plus currents be sent through the ring when odd-numberedcoils are in bearing with the brushes, and re versed, negative, or minuscurrents are Sent when even-numbered segments are in bearing with thesame brushes, these reversed currents will maintain the polarity of thering constant. Thus let the terminals :land F at A be the poles of asource of alternating or reversed currents of any given periodicity, andlet it be assumed that the first, say, direct impulse proceeds in thedirection shown by the single arrows from i through machinebrush m b tothe Gramme ring at the point S down both sides of the ring to n, outmachine-brushm 5 back to source F at A. This impulse will make a southpole in the ring at s and a north poleatn. At the same time current willflow through the shunt fieldscircuit connected to the brushes f b and fb in the direction shown by the arrows, creating the field N N, S S,- asindicated, and under the action of this direct impulse motion will onsue in the direction indicated by the arrows r r opposite the hands of aclock; It, now,

it be assumed that under this first impulse.

the armature turns through the are coveredby one single bar of thecollector, and a re verse impulse is sent from the source it at A, asindicated by the double arrows in the main circuit, then, as thedirection of this impulse is opposite to the former, it may be regardedfor convenience of analysis as entering the machine at the lower brush mb i which, after the motion assumed to have taken place under the firstimpulse, will then be bearing upon the segment a of the commutator, andbrush m1) will likewise bear upon segment a and the current shown by thedouble arrows will flow in at brush m b to segment a whence it will gothrough the aux iliary connection shown around to the opposite side ofthe ring, entering at coil 2 0p posite segment a and from this point ofthe ring it will flow downward on both sides to the right and left inthe same direction as before to the point 8 on the ring, then out theauxiliary connection,- as shown by the arrows, around to segment cc, andout brush m 12, back to source :1: at 7A, thus completing the circuit ina direction opposite to the former,- but still in thesame direction inthe coils of the ring, and so maintaining with this reversed impulse asouth polarity in the ring at s and a north polarity at n, as before;Thus motion will continue in the same direction as before, providing thefield-poles have not been changed; but the field-circuit is connected tothe brushes f I) f b which bear upon the ordinary Gramme collector, andas We have seen that current must always flow in the same directionthrough the ring with these reversed currents, it must likewise flow inthe same di-' rection from the brushes f b fb bearing upon the ordinarycollector of this ring. Therefore with alternating currents in theexternal circuit there will always be currents of one direc:

tion in the ring itself flowing uniformly and,

constantly down both sides from s to a, and likewise out the brushes f bfb maintaining a constant field N N, S S, as shown. o have thereforepractically a direct-current motor on an alteruatin g-current circuitresulting from a system of connections which has practically the effectof shifting the brushes in position from one side of the ring to theother at each reversal of the current; and this system of connectionsconstitutes an important modification of the Gramme machine, for whilesuch a system makes the ring absolutely inoperative with a directcurrent it renders it operative with an alternating current. It will beobserved, however, that if the brushes m b and on b be lifted off thecommutator a a &c., and the terminals of a direct-current circuit beconnected to the brushes fl) and f b the machine then becomes anordinary direct-current Gramme motor, with the fields in shunt relationto the armature, and the machine thus loses none of its value as adirect-current motor, while by the addition of the reversely-connectedbrush-changer a a &c., to the ordinary Gramme machine it can be used asan ordinary direct-current motor or as an alternating-current motor atpleasure.

My invention therefore consists in adding to an ordinary armature andcollector connected in the usual way an additional or auxiliarycollector having the same number of bars as the former, but withsuccessive bars connected to diametrically opposite points of thecontinuous ring-winding.

Fig. 2 shows the application of the system or method to an ordinarydirect-current motor having any form of cylinder or drum armaturewinding, the Froelich winding being selected for illustration. Theconnections are the same as in the figure previously described, exceptthat the ordinary commutator f f &c., is shown outside, and the otherreversely connected commutator is shown inside, and this auxiliarycommutator, which I designate as a brush-changer, instead of beingconnected to the winding of the armature, is connected to correspondingbars of the other collector, which amounts, in fact, to the same thing,and the source of at ternating current i and y A is shown inside thelatter ring The arrowheads indicate the direction of current-fiowthroughout the winding.

In Fig. 3 is shown an enlarged view of the system of connecting the twosets of commutators to each other, the outside ring being the ordinarydirect-current commutator, the inside one being the reverselyconnectedbrush-changer.

I will now explain why the machine is a self-starting one with analternating current; why it will not turn indiiiferently in eitherdirection, but has a single direction of rotation with such a current;why there is never with the machine in motion any reversal of thepolarity of the iron cores, and why the machine is not a synchronousmotor. It is well known that any such form of directcurrent motor willstart when actuated by an alternating current, for if a plus impulseinduces the polarities shown, N N, S S in the field and s n in thearmature-ring, and the machine remains motionless until a reversedcurrent is sent, then both the field and armature polarities arereversed simultaneously, and the tendency to motion is still in the samedirection as indicated by the arrows. The tendency to motion istherefore continuous and in the same direction, polarities of the ironmasses being reversed at each reversal of current until the machinestarts; but, once started, these polarities are all constant. Themachine therefore starts as an ordinary direct current machine connectedin an alternating-current circuit. The reasons just given explain, also,why the machine cannot move indilterently in either direction. They alsoexplain why there is no change of magnetic polarity in the iron coresafter the machine has moved through the are covered by onecollector-bar.

It remains to show why the machine is not synchronous with the generatorand does not have to start at the same speed as the generator. From theanalysis given it is evident that when in motion, as contemplated, onebar of the collector must pass under the brushes at each reversal ofcurrent. The number of collector-bars therefore represents the number ofcurrent reversals that correspond to a single complete revolution of themotor-armature. Thus, let it be supposed for illustration that thesource of alternating current at A is an altern ating-current dynamohaving ten field-poles and a speed of fifteen hundred revolutions perminute. There will be ten reversals of current produced in eachrevolution of the dynamo armature. It, therefore, the Gramme rin g beprovided with a collector having thirty bars it will make one revolutionfor thirty reversals of current, and will therefore make one revolutionin the same period of time that the dynamo-armature makes threerevolutions, and if the dynamo speed is assumed to be fifteen hundredper minute the motor speed will be five hundred per minute and constant,and the speed of the motor will always be defined by the ratio of thenumber of current reversals produced in a single revolution of thedynamo to the number of collector-bars connected to the ring.

I claim- '1. The method of operating an electric motor connected in analternating-current circuit, which consists in giving a constant polarity to a continuously-wound armature by delivering the alternatingimpulses successively to opposite sides of the armature-wind- 111g.

2. The method of operating an electric motor connected in analternating-current circuit, which consists in giving a constantpolarity to a continuously-wound armature-circuit by sending theopposite impulses of ourmy invention I have hereunto setmy handf rentsuccessively to opposite sides of the this 17th clay of July, 1889, inthe presence armature-winding, and in giving a constant of twoWitnesses. polarity to the field-magnet by a similar and FRANCIS JARVISPATTEN.

5 simultaneous delivery of the same impulses WVitnesses:

to the field-circuit. W. M. MINER,

In testimony that I claim the foregoing as A. B. FRENZEL.

